CN104215357A - Aquatic product cold chain temperature measurement system and method based on optical fiber sensor - Google Patents

Abstract

The invention provides an aquatic product cold chain temperature measurement system and an aquatic product cold chain temperature measurement method based on an optical fiber sensor. The aquatic product cold chain temperature measurement system based on the optical fiber sensor comprises an optical fiber grating array, a temperature measurement control terminal and a monitor computer, wherein the optical fiber grating array is connected with the temperature measurement control terminal, and the temperature measurement control terminal is connected with the monitor computer through a local area network. The aquatic product cold chain temperature measurement system and the aquatic product cold chain temperature measurement method based on the optical fiber sensor use the separation characteristic of an optical fiber sensing probe and a collection control circuit, prevent electronic components from working under low temperature environment, and achieve accurate measurement for temperature at each position of an aquatic product cold chain.

Description

Aquatic product cold chain temperature measurement system and method based on optical fiber sensor

technical field

The invention relates to a cold chain temperature measurement system, in particular to a cold chain temperature measurement system based on fiber grating temperature measurement technology.

Background technique

In the grain, food, and aquatic product industries, many grains, food supplies, and cold fresh products are stored and kept in a constant temperature environment, and some need to be stored in a low temperature environment. The traditional management mode is manual management or traditional sensor temperature measurement.

The manual management method is to manually record the reading of the thermometer on the storage container and form a manual report. This method is limited by the artificial reading accuracy, and the reliability is not high.

The traditional sensor temperature measurement method is to use thermistor method or thermocouple method to measure the temperature at a specific position of the container. In this form, the reliability of the temperature measuring device is low in a low temperature environment, and the temperature measuring circuit of the sensor is prone to failure or mismeasurement. .

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art and provide a system and method for measuring temperature in the cold chain of aquatic products based on optical fiber sensors. Working down, the accurate measurement of the temperature of each position of the aquatic product cold chain has been realized.

The technical solution provided by the present invention is: an aquatic product cold chain temperature measurement system based on an optical fiber sensor, including an optical fiber grating array, a temperature measurement control terminal and a monitoring computer. Connected to the monitoring computer.

In the system, the fiber grating array includes M fiber grating sensing fibers and transmission fibers connected, wherein each fiber grating sensing fiber is provided with N fiber Bragg gratings; the transmission fiber is connected to a temperature measurement control terminal.

In the system, the temperature measurement control terminal includes sequentially connected M*N or M optical switches, a temperature sampling module, a processor and a communication module, the optical switch is connected to the fiber grating array sensing fiber, and the communication module is connected to the local area network.

In the system, the local area network adopts wired or wireless local area network.

The temperature measurement method of aquatic product cold chain based on optical fiber sensor includes: using fiber grating array to measure temperature, each fiber grating sensing fiber has multiple fiber Bragg gratings, one fiber Bragg grating is a temperature measurement point, and the temperature measurement control terminal The temperature sampling module performs temperature demodulation and network temperature measurement on all the fiber Bragg gratings in the sensing fibers selected by the on-off of M optical switches at the same time, or on the fiber Bragg grating sensing fibers selected by the on-off of M optical switches, the selected On each fiber grating sensing fiber, the fiber Bragg grating selected by N optical switches is used for temperature demodulation and network temperature measurement at the same time, and then the temperature information of the measured distribution points is transmitted to the monitoring computer through the local area network. Realize real-time temperature monitoring of all temperature measuring points in the entire aquatic product cold chain on the computer.

Advantages of the present invention: the present invention organically combines optical fiber temperature measurement technology, communication technology, and computer measurement and control technology, realizes a cold chain temperature measurement system for aquatic products based on optical fiber sensors, and improves the efficiency of traditional cold chain temperature measurement systems , The characteristics of poor system stability, high temperature measurement accuracy, and flexible use. The present invention specifically comprises following characteristics:

Resistant to extreme temperatures, the temperature range is as low as -40 to 250°C;

The temperature measurement accuracy is high, with an error of plus or minus 0.1°C;

High reliability, service life up to 20 years;

Small size, easy installation;

It is safe to use, the probe is insulated, the electrical isolation is good, no electric spark is generated, and the fire is effectively prevented.

Description of drawings

Fig. 1 is a schematic block diagram of the system structure of the present invention.

Fig. 2 is a schematic diagram of the internal hardware framework of the temperature control terminal and the connection mode of the temperature measuring sensor according to the present invention.

Detailed ways

The optical fiber sensor-based aquatic product cold chain temperature measurement system includes: a monitoring computer, an optical fiber temperature measurement control terminal, and an optical fiber temperature measurement sensor head. The monitoring computer is connected to the optical fiber temperature measurement control terminal through a wired or wireless LAN. The optical fiber temperature measurement control terminal is connected to the optical fiber temperature measurement sensor head through optical fiber to collect temperature data in real time. The temperature measurement control terminal uses an optical receiver to connect two or more optical fiber sensor systems in parallel, and adopts time division multiplexing to realize multi-point asynchronous real-time temperature collection. The acquisition system can not only collect multi-point temperature data in real time, but also store historical temperature data information.

The above-mentioned multiple monitoring hosts are connected through a wired or wireless local area network.

The optical fiber temperature sensing head adopts the sensing principle of optical fiber grating, and uses the selective reflectivity of broadband spectrum in the optical fiber grating and the temperature sensitivity of the optical fiber grating to measure temperature.

The temperature measurement control terminal in question includes a temperature sampling module, an optical switch, a processor, and a communication module; the temperature control terminal uses a high-performance processor to manage each module to achieve the required functions, and the temperature acquisition terminal collects multiple temperature measurement sensors in time through the optical switch The temperature at the location; the temperature control terminal is connected to a wired or wireless LAN through a communication module to exchange data with the monitoring terminal (ie, the monitoring host).

The present invention will be further described in detail below in conjunction with specific embodiments.

The invention utilizes the advantages of the optical fiber sensor such as anti-flammability, anti-corrosion, and high temperature measurement accuracy, and applies it to a cold chain temperature measurement system to detect abnormal temperature conditions in the cold chain storage process early, so as to take effective countermeasures in time to prevent Serious quality problems and related losses occurred during cold chain storage.

The aquatic product cold chain temperature measurement system based on fiber grating sensors includes a monitoring computer, a temperature measurement control terminal, and a fiber grating array sensing fiber, and the monitoring computer is connected to the temperature measurement control terminal through a wired or wireless local area network.

The multiple monitoring hosts are connected through a wired or wireless local area network.

The temperature measurement control terminal is connected to the optical fiber temperature measurement probe through an optical fiber to collect temperature data in real time.

The temperature measurement control terminal uses an optical switch to connect two or more sensing optical fibers in parallel, and adopts time division multiplexing to realize multi-point asynchronous real-time temperature acquisition.

The acquisition system can not only collect multi-point temperature data in real time, but also store historical temperature data information.

The present invention will be further described below in conjunction with accompanying drawing and example.

The fiber grating sensor and temperature control terminal used in the present invention is a temperature measurement system that utilizes the wavelength selective reflection of the broadband spectrum in the fiber grating and the sensitivity of the reflection spectrum to the temperature of the fiber grating, and has the ability to withstand extreme temperatures , High temperature measurement accuracy, high reliability, convenient installation, safe use and other characteristics, suitable for temperature detection, control and corresponding quality assurance in all links of cold chain storage.

In the implementation of the present invention, a fiber Bragg grating (FBG) with a central reflection wavelength of 1540nm to 1545nm is selected to make a sensing fiber, and each sensing fiber contains 5 FBGs, namely FBG1, FBG2, FBG3, FBG4, and FBG5;

In the implementation of the present invention, in the temperature measurement control terminal, the fiber grating wavelength demodulation module of Bay Spec Company is selected as the temperature acquisition sampling module, and its sampling rate is 5K. In each sampling, the sampling module can simultaneously measure one Sensing the offset of the central wavelength of the reflected light caused by the temperature change of the five fiber gratings FBG1, FBG2, FBG3, FBG4, and FBG5 on the optical fiber, and calculating the temperature information corresponding to the position of the fiber grating; the temperature sampling module passes a 1×4 optical switch is connected to 4 sensing optical fibers; the processor in the temperature measurement control terminal controls the optical switch to gate different sensing optical fibers in one cycle (0.5S), and controls the sampling module to sample; Finally, the measured temperatures of all 20 points on the 4 sensing optical fibers in one cycle (0.5S) are sent to the monitoring computer through the communication module.

In the implementation of the present invention, multiple sets (3 sets were used in the specific implementation) of the combination of measurement control terminals and sensing optical fibers are used to measure the temperature of the temperature measurement points required in the cold chain, and the temperature of the cold chain is measured in the monitoring computer. The internal geographical location (temperature position) of the chain is modeled to realize real-time and intuitive temperature measurement of the entire cold chain.

As shown in Figure 1, the cold chain temperature measurement system based on optical fiber sensors includes: a monitoring computer, an optical fiber temperature measurement control terminal, and a fiber grating sensing optical fiber. The monitoring computer is connected to the optical fiber temperature measurement control terminal through a wired or wireless LAN. The temperature information at the locations of multiple temperature measuring sensors is displayed, and the optical fiber temperature measuring control terminal is connected to the optical fiber temperature measuring sensor head through an optical fiber to collect temperature data in real time.

As shown in Figure 2, the temperature measurement control terminal based on the optical fiber sensor includes a processor, and a high-performance embedded high-speed processor is used to manage each sub-module of the temperature control terminal. The temperature information of the optical fiber is demodulated to collect multi-point temperature signals. The processor reads the signal of the temperature acquisition module, and calculates the temperature information of the positions where the multiple fiber grating sensors are located. The temperature control terminal communication module is connected with the wired/wireless local area network.

In a word, the present invention provides a cold chain temperature measurement system for aquatic products based on fiber grating sensors, which includes multiple monitoring computers, multiple parallel temperature control terminals, and fiber grating array sensing fibers. Multiple parallel temperature measurement control terminals are connected to display the temperature at the position of the optical fiber grating in all sensing fibers in real time, which improves the traditional cold chain temperature monitoring method of aquatic products, improves the temperature monitoring accuracy of each link in the cold chain storage of aquatic products, and improves the quality of aquatic products. Cold chain quality management system.

Claims (5)

1. An aquatic product cold chain temperature measurement system based on optical fiber sensors, characterized in that: it includes a fiber grating array, a temperature measurement control terminal and a monitoring computer, the fiber optic grating array is connected to the temperature measurement control terminal, and the temperature measurement control terminal is connected to the monitoring computer through a local area network connected. 2. The system according to claim 1, characterized in that: the fiber grating array comprises connected M fiber grating sensing fibers and transmission fibers, wherein each fiber grating sensing fiber is provided with N fiber bragg gratings; The optical fiber is connected with the temperature measurement control terminal. 3. The system according to claim 2, characterized in that: the temperature measurement control terminal includes sequentially connected M*N or M optical switches, a temperature sampling module, a processor and a communication module, the optical switch and the fiber grating array sensor The optical fiber is connected, and the communication module is connected with the local area network. 4. The system according to claim 1, characterized in that: the local area network adopts wired or wireless local area network. 5. The method for measuring temperature in the cold chain of aquatic products based on optical fiber sensors is characterized in that it includes: using a fiber grating array to measure temperature, each fiber Bragg grating sensing fiber has a plurality of fiber Bragg gratings, one fiber Bragg grating is a temperature measurement point, The temperature sampling module of the temperature measurement control terminal performs temperature demodulation and network temperature measurement on all the fiber Bragg gratings in the sensing fibers selected by the on-off of the M optical switches, or performs temperature measurement on the fiber Bragg gratings selected by the on-off of the M optical switches. Sensing optical fiber, each selected fiber Bragg grating sensing fiber, and the fiber Bragg grating selected by N optical switches are used for temperature demodulation and network temperature measurement at the same time, and then the temperature information of the measured distribution points is passed through the local area network. Pass it to the monitoring computer, and realize real-time temperature monitoring of all temperature measuring points in the entire aquatic product cold chain on the computer.